器件名称:
AD8842
功能描述:
8-Bit Octal, 4-Quadrant Multiplying, CMOS TrimDAC
文件大小:
506.43KB 共12页
简 介:
a FEATURES Low Cost Replaces 8 Potentiometers 50 kHz 4-Quadrant Multiplying Bandwidth Low Zero Output Error Eight Individual Channels 3-Wire Serial Input 500 kHz Update Data Loading Rate ± 3 V Output Swing Midscale Preset, Zero Volts Out APPLICATIONS Automatic Adjustment Trimmer Replacement Vertical Deflection Amplitude Adjustment Waveform Generation and Modulation VDD 8-Bit Octal, 4-Quadrant Multiplying, CMOS TrimDAC AD8842 FUNCTIONAL BLOCK DIAGRAM DECODED ADDRESS 8 LOGIC DATA 4 SDI 8 SERIAL REGISTER 8X 8 DAC R E G I S T E R S 8 DAC A VOUT A VIN A G LD AD8842 VIN H 8 G DAC H VOUT H CLK GND VSS SDO PR GENERAL DESCRIPTION The AD8842 provides eight general purpose digitally controlled voltage adjustment devices. The TrimDAC capability allows replacement of the mechanical trimmer function in new designs. The AD8842 is ideal for ac or dc gain control of up to 50 kHz bandwidth signals. The four-quadrant multiplying capability is useful for signal inversion and modulation often found in video vertical deflection circuitry. Internally the AD8842 contains eight voltage output digital-toanalog converters, each with separate voltage inputs. A new current conveyor amplifier design performs the four-quadrant multiplying function with a single amplifier at the output of the current steering digital-to-analog converter. This approach offers an improved constant input resistance performance versus previous voltage switched DACs used in TrimDAC circuits, eliminating the need for addi……
